Cathode mounting



Jab. 21, 1947.

E. c. OKRESS ETAL CATHODE MOUNTING Filed May 13, 1943 INVENTOR5 EC OKEESS D E NEZ-SO/V. BY -'1 Patented Jan. 21, 1947 UNITED STATES PATENT OFFICE CATHODE MOUNTING Ernest C. Okress, Montclair, and Donald E. Nelson, East Orange, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application May 13, 1943, Serial No. 486,752

Claims. 1

This invention relates to improvements in cathode mounting, and while applicable more es pecially to cathode mounting in magnetrons, is of advantage in other devices.

One of the difficulties encountered with cathodes is the presence of vibration therein, caused not only by mechanical forces, such as vibration in an airplane where the device may be used, but also by other causes. With ultra high frequency generation mechanical vibrations in a cathode may seriously affect operating characteristics, and it therefore becomes desirable to reduce and eliminate vibration as far as possible.

Accordingly, an object of the present invention is to accomplish the desired reduction of cathode vibration.

Another object of the invention is to establish maximum rigidity between the cathode and anode and thereby avoid relative vibration between those electrodes.

A further object of the invention is to obtain a rigid relation between cathode and anode with minimum change in present-day structure of the electronic device.

A still further object of the invention is to avoid deleterious effects of the high frequency current on the ceramics or other insulators employed, and, conversely, to avoid undesired shorting or other ill effects in the high frequency current.

Other objects of the invention will appear as the description progresses, both by direct recitation thereof and by implication from the context.

- Referring to the accompanying drawing in which like numerals of reference indicate similar parts in both views:

Figure 1 is a vertical and diametric section of a magnetron embodying the present invention, taken on the line 1-1 of Fig. 2; and

Figure 2 is a sectiona1 plan of the magnetron immediately below the cover plate, as on the line 11-11 of Fig. 1.

In the specific embodiment of the invention illustrated in said drawing, a magnetron body In is shown of generally cylindrical configuration and provided with end-spaces II sealed vacuum tight by end or cover plates l2. Within the magnetron and in direct communication with and between said end-spaces, is an axial cavity l3 from which radiate suitable resonant cavities It which are open-ended into the end-spaces ll. Between the radiating resonant cavities It the body it is accordingly formed with radiating segments 55 thereby forming what may be termed a split anode. Within and axially of the central or axial cavity I3 is a cathode it, here shown as cylindrical and hollow for purposes of indirect heating thereof by a coiled heater l! extending coaxially through the cathode. End insulators l8 are provided for the cathode, the ends of the heater H extending through the insulators, and over the outer ends of the insulators are metallic plates or discs 19 spaced by the insulators Hi from the said cathode l6 and juxtaposed flatwise upon the ends of said insulators. The ends of the heater filament I! are electrically connected, as will presently appear more in detail, to the said plates or discs I 9, and also connected to said plates, by welding or otherwise, are appropriate lead-in wires 20 sealed vacuum tight where passing to the exterior of the magnetron. It is usual practice, and here so shown, to extend the leadin wires 20 for the filament or heater i'l radially through the end spaces II and out through a flange portion 2| forming a rim at the edge of the body portion of the magnetron.

In most respects, the magnetron as above described is in accordance with the construction of magnetrons as heretofore manufactured. The improvement of the present invention resides primarily in the support for the cathode i6 and mounting and connection of the filament H with respect to said plates or discs I9.

According to the embodiment shown, the end insulators I8 for the cathode and plate or disc I9 are both centrally apertured to receive a neck portion of a metallic cylindrical head or terminal 22 of which the part beyond the disc has larger diameter than the said neck portion. This terminal 22 is welded or otherwise secured to the said disc. Said terminal 22 is provided with a longitudinal axial hole therethrough for reception of the end of the filament and the filament in turn is welded, soldered, riveted or otherwise made fast at its outer end to the outer end of the terminal. The structure thereby affords electrical connection from the filament end to the disc l9 and lead-in 20.

superposed on the outer face of the disc, coaxial therewith, is a dielectric support 23 here shown in the form of a stepped and hollow cylindrical construction, with the smaller end next said disc and the outer larger end next the magnetron cover or end plate I2. The smaller end fits around the metallic filament terminal 22, whereas the larger outer end is seated in a circular socket 24 provided for the purpose in the inner face of the magnetron cover plate l2. Since the structure is duplicated at the other end of the cathode, it will now be apparent that the age breakdown between the end plate l2 and the,

cathode disc or plate l9 due to the direct current voltage. The bulk of the radio frequency field 5. A cathode mounting comprising a magnetron body having cover plates maintaining a vacuum-tight seal for the interior of said body, and said cover plates having sockets at the inner faces thereof and wholly within the magnetron body, a cylindrical cathode Within said body situated ndwise between sai sockets, and insulating supporting means in part within said sockets and interposed between said plates and cathode entirely within said body supporting said cathode from the plates.

6. A cathode mounting comprising a hollow cathode having an insulator in the end thereof,

a conductive plate at the outer end of said insulator, another insulator beyond said plate, filament-contacting means within the second-mentioned insulator, and a filament within said cathis in the peripheral region of the end space in the vicinity of the resonant cavities, and the dielectric support 23 is remote therefrom so as not to be exposed to the radio frequency fields of too great intensity as compared with the fields in the resonators.

We claim: 7

1. A cathode mounting comprising a cylindrical cathode, insulators at the ends of and fixed to said cathode, said insulators havin flat outer ends, transverse conductive discs in flatwise engagement with said outer ends of said insulators, and means having flatwise engagement with cuter surfaces of said discs in opposition to saidinsulators substantially immovably supporting the cathode.

2. A cathode mounting comprising a magnetron body having cover plates maintaining a vacuum-tight seal for the interior of said body, a cylindrical cathode Within said body situated endwise between said plates, said plates having sockets at the inner faces thereof opposite the ends of the cathode, and means interposed between said plates and cathode and located in part in said sockets and supporting said cathode from the plates. 3. A cathode mounting comprising a magnetron body having cover plates maintaining a vacuum-tight seal for the interior of said body, a cylindrical cathode within said body situated endwise between said plates, said plates having sockets at the inner faces thereof opposite the ends of the cathode, an insulating means interposed between said plates and cathode and located in part in said sockets and supporting said cathode from the plates.

4. A cathode mounting comprising a magnetron body having cover plates maintaining a vac- Hum-tight seal for the interior of said body, and said cover plates having sockets at the inner faces thereof and wholly within the magnetron body, a cylindrical cathode within said body situated endwise between said sockets, and means in part within said sockets and interposed between said plates and cathode entirely within said body sup porting said cathode from the plates.

ode and projecting into said second-mentioned insulator and secured to said filament-contacting means.

- 7. A cathode mounting comprising a hollow cathode having an insulator in the end thereof, a conductive plate at the outer end of said insulator, another insulator beyond said plate, filament-contacting means within the second-mentioned insulator in contact with and secured to said conductive plate, and a filament within said cathode and projecting into said second-mentioned insulator, and secured to said filamentcontacting means.

8. A cathode mounting comprising a supporting insulator of tubular and stepped formation by which the insulator has a large end and a small end, a cover plate having a socket receiving the large end of said insulator, a conductive plate at the small end of said insulator, conductive means within said insulator connected to said plate, a filament secured to said conductive means and extending out of and away from said insulator, a cathode around said filament, and means securing the cathode in fixed position with respect to said insulator and plate. 9. A cathode mounting comprising a cathode, a filament within said cathode with the ends of the filament projecting at the ends of the oathode, a support opposite the end of the cathode, a terminal on said filament, said terminal being within and held by said support, and a conductive plate between said support and cathode and secured to said terminal.

10. A cathode mounting comprisin a cathode, a filament within said cathode with the ends of the filament projecting at the ends of the oathode, a support opposite the end of the cathode, a terminal on said filament, said terminal being within and held by said support, a conductive plate between said support and cathode and secured to said terminal, and an insulator between said plate and cathode, said filament end passing through said insulator.

ERNEST C. OKRESS. DONALD E. NELSON... 

